where \(\widehat{{\bf F}}_1\)  is of size \(m\times m\) , \(\widehat{{\bf F}}_2\) 
\(m\times (b-m)\) , \(\widehat{{\bf F}}_3\)  \((b-m)\times m\) , and
\(\widehat{{\bf F}}_4\)  \((b-m)\times (b-m)\) . By using the property of the
determinant of block matrices [1]}, we have:
\( |\widehat{{\bf F}}| = |\widehat{{\bf F}}_4||\widehat{{\bf T}}| \,,\) 
